/*
 * Copyright (c) 2007 innoSysTec (R) GmbH, Germany. All rights reserved.
 * Original author: Edmund Wagner
 * Creation date: 01.06.2007
 *
 * Source: $HeadURL$
 * Last changed: $LastChangedDate$
 * 
 * the unrar licence applies to all junrar source and binary distributions 
 * you are not allowed to use this source to re-create the RAR compression algorithm
 * 
 * Here some html entities which can be used for escaping javadoc tags:
 * "&":  "&#038;" or "&amp;"
 * "<":  "&#060;" or "&lt;"
 * ">":  "&#062;" or "&gt;"
 * "@":  "&#064;" 
 */
package ir.mahdi.mzip.rar.unpack.ppm;

import ir.mahdi.mzip.rar.io.Raw;

public class State extends Pointer {

    public static final int size = 6;

    public State(byte[] mem) {
        super(mem);
    }

    public static void ppmdSwap(State ptr1, State ptr2) {
        byte[] mem1 = ptr1.mem, mem2 = ptr2.mem;
        for (int i = 0, pos1 = ptr1.pos, pos2 = ptr2.pos; i < size; i++, pos1++, pos2++) {
            byte temp = mem1[pos1];
            mem1[pos1] = mem2[pos2];
            mem2[pos2] = temp;
        }
    }

    public State init(byte[] mem) {
        this.mem = mem;
        pos = 0;
        return this;
    }

    public int getSymbol() {
        return mem[pos] & 0xff;
    }

    public void setSymbol(int symbol) {
        mem[pos] = (byte) symbol;
    }

    public int getFreq() {
        return mem[pos + 1] & 0xff;
    }

    public void setFreq(int freq) {
        mem[pos + 1] = (byte) freq;
    }

    public void incFreq(int dFreq) {
        mem[pos + 1] += dFreq;
    }

    public int getSuccessor() {
        return Raw.readIntLittleEndian(mem, pos + 2);
    }

    public void setSuccessor(int successor) {
        Raw.writeIntLittleEndian(mem, pos + 2, successor);
    }

    public void setSuccessor(PPMContext successor) {
        setSuccessor(successor.getAddress());
    }

    public void setValues(StateRef state) {
        setSymbol(state.getSymbol());
        setFreq(state.getFreq());
        setSuccessor(state.getSuccessor());
    }

    public void setValues(State ptr) {
        System.arraycopy(ptr.mem, ptr.pos, mem, pos, size);
    }

    public State decAddress() {
        setAddress(pos - size);
        return this;
    }

    public State incAddress() {
        setAddress(pos + size);
        return this;
    }

    public String toString() {
        StringBuilder buffer = new StringBuilder();
        buffer.append("State[");
        buffer.append("\n  pos=");
        buffer.append(pos);
        buffer.append("\n  size=");
        buffer.append(size);
        buffer.append("\n  symbol=");
        buffer.append(getSymbol());
        buffer.append("\n  freq=");
        buffer.append(getFreq());
        buffer.append("\n  successor=");
        buffer.append(getSuccessor());
        buffer.append("\n]");
        return buffer.toString();
    }
}
